Pancreatic metastasis of extra-skeletal mesenchymal chondrosarcoma diagnosed by ultrasound endoscopy-guided fine-needle aspiration.

A 47-year-old man with a history of ESMC resection of the left chest wall seven years ago was admitted to our hospital due to mid-upper abdominal pain and jaundice for more than 10 days. Laboratory tests showed elevated direct bilirubin, alanine aminotransferase, gamma-glutamyltranspeptidase, and alkaline phosphatase. Computed tomography (CT) of the abdomen revealed soft tissue mass in the head and body of the pancreas with irregularly shaped calcifications, and an enhanced scan showed heterogeneous enhancement. Combined with the patient's past medical history, the possibility of pancreatic metastasis of ESMC was considered. After anti-inflammatory, hepatoprotective, and cholagogical treatment jaundice improved, and ultrasound endoscopy-guided fine-needle aspiration (EUS-FNA) was performed to clarify the nature of the mass, which showed a 4.1*4.2 cm mixed echogenic area with internal calcification in the head of the pancreas. Aspiration pathology showed proliferation of short spindle and round cells into nests, the immunohistochemistry stain showed CD99 (+); CD34, CD117, Dog-1, and S-100 were negative. Pancreatic metastasis of ESMC was diagnosed. Four months later, endoscopic biliary metal stent drainage (EMBD) was performed when the patient developed obstructive jaundice again due to lesion progression. PET/CT at a 2-year follow-up showed multiple high-density calcifications and abnormally increased FDG metabolism throughout the body.